a) Field of the Invention
The present invention is directed to a fast, nondestructive measurement method for determining the substances contained in solid, liquid and/or suspended flowing organic compounds. The proposed solution is suitable for calibration to a large number of relevant parameters and can be used in all fields, particularly also in a mobile manner.
b) Description of the Related Art
The through-flow measurement cuvette described in DE 100 16 023 C2 is suitable for the combined use of spectroscopy and polarimetry for the simultaneous determination of a plurality of measured quantities in physical-chemical and bio-technical processes. In particular, substances dissolved in flowing media can be detected continuously and without a delay in time and can be quantitatively determined. Wavelengths in the UV region to the NIR region can be used for spectroscopic measurement. The measurement path is located between two rods of glass, or the like, projecting into the measurement cuvette transverse to the flow direction. Depending on the substance to be investigated, the measurement path must be varied by displacing the rods because measurements can only be carried out by transmission. However, this makes it more difficult or impossible to use the through-flow measurement cuvettes for automated, mobile use.
The determination of the contents of liquid manure, for example, with a view to the precise use thereof as organic fertilizer, is particularly important. Heretofore, the applicable guidelines in this case with regard to the maximum amount to be dispensed could be adhered to only with difficulty because an exact determination of the components and concentrations at the moment of dispensing was impossible. It was only possible to monitor adherence to guidelines through soil analyses before or after dispensing.
According to the known prior art, the determination of the contained substances is carried out after taking samples by subsequent wet chemical measurements in the laboratory. This method is time-consuming and requires extensive preparation of samples. The quantity of samples is limited, and the analysis data can be used for controlling and/or regulating processes in a timely manner only to a limited extent if at all. When the measurement is carried out in through-flow cells with conventional sensors, only the contents that are measurable selectively by the respective sensors can be detected.
A project (“Analysis of Nutrients in Hog Manure by Field-portable Near-infrared Spectroscopy”, July 2001) conducted by PDK Projects, Inc., documents the use of NIR spectroscopy for determining components and concentrations of organic waste. However, the results of this project relate only to the use of spectroscopic measuring instruments under laboratory use. The samples to be determined were placed on the spectroscopic measurement head for this purpose. A compact solution for a possible mobile use on a vehicle for dispensing liquid manure was not the aim of the project.